Title page for ETD etd-01242012-201855

Assessment of Stink Bug Feeding Damage in Louisiana Soybean: Use of a No-Choice Feeding Field Protocol

Degree

Master of Science (M.S.)

Department

Entomology

Advisory Committee

Advisor Name

Title

Leonard, Billy Rogers

Committee Chair

Davis, Jeffrey

Committee Member

Padgett, Guy Boyd

Committee Member

Story, Richard

Committee Member

Willrich-Siebert, Melissa

Committee Member

Keywords

Glycine max

Hemiptera

Pentatomidae

Date of Defense

2011-12-13

Availability

unrestricted

Abstract

Numerous arthropods are pests of soybean in the subtropical environment of Louisiana. The most important pod-feeding guild includes a complex of stink bugs (Hemiptera: Pentatomidae). One of these species, redbanded stink bug (Piezodorus guildinii [Westwood]), has emerged as a significant pest in Louisiana soybean. Currently, limited information is available describing soybean plant injury from this pest in the United States or compares injury relative to native stink bugs. Therefore, a field protocol was modified to assess injury to soybean seeds. Studies conducted in Louisiana during 2009-2011 used procedures to isolate the effects of infestation duration (24-96 h after infestation [HAI]) on seed injury at selected pod stages (R5-R6.5). In addition to redbanded stink bug; seed injury from brown stink bug, Euschistus servus (Say); and E. quadrator (Rolston) also was evaluated. For the infestation duration experiments, all injury to immature seed was significant between treatments (non-infested and infested pods). Injury to immature seed in R5.5 stage pods peaked (P=0.0102) by 72 HAI for redbanded stink bug. Injury to immature seed in R5 stage soybean pods peaked (P=0.0084) by 96 HAI for brown stink bug. For mature seed injury and weights significant differences (P<0.0001) between non-infested and infested pods were detected for all species. A second experiment evaluated seed injury among pod stages (R5-R6.5). Immature and mature seed injury was not significantly different (P>0.05) among pod stages for any species. Weights of mature seed were significantly lowest for redbanded stink bug (P=0.0177) and E. quadrator (P=0.0261) infestations during the R5 and R5.5 stages. Based upon mature seed weights similar levels of injury were produced by native infestations and caged stink bugs. Non-injured seed did not compensate for injured seed within the same pod. These results add to our understanding of stink bug-induced seed injury during selected pod stages and will allow further improvement to Louisiana soybean IPM recommendations.